1. The Field of the Invention
This invention relates to laboratory workbenches and, more specifically, product protection workbenches having a protective screen partially covering a working space.
2. Present State of the Art
A conventional laboratory workbench includes a housing having a working space. A window borders the working space on one side thereof. A fan produces a flow of air in the working space, and a protective screen is arranged on the housing in such a way that it can be moved. Such laboratory workbenches are known from GB 2 112 927 A or from US-A-4 179 984, for example. The company brochure "Heraeus Biological Safety Workbenches Laminair HB and HBB" of Heraeus Instruments GmbH also discloses such a laboratory workbench.
Laboratory workbenches are generally used to protect the product being handled or processed in them, the operator, and/or the environment. Safety is ensured by a suitable flow of air. Laboratory workbenches which emphasize product protection are intended to prevent contamination from the surroundings penetrating into the working space. For this purpose, a flow of air which is produced by the fan is aimed from the working space through the window to the outside.
Partially covering the window by a protective screen through which an operator can observe the operation within the working space is known from GB 2 112 927 A. On occasion, it is necessary that the protective screen be removed from the window so that the full size of the window is open. For this purpose, folding the protective screen up on the outside and also laying it on the top of the housing is known from US-A-4 179 984. Folding up the protective screen on the outside of the housing not only requires available space, but also harbors some safety risks when it is operated. This is because, for a number of reasons, the frame of such a protective screen is kept very thin and inconspicuous, as a rule. As such, there is the danger that a person in the vicinity could injure himself on the protective screen folded up outside of the housing if he did not see or was not aware of the protective screen.